The first is a triggered ability: "When this permanent enters, target player may search their library for a card named [name], reveal it, put it into their hand, then shuffle." (2025-06-06) Note that the target player searches their library (which may be affected by effects such as that of Stranglehold) and that the card they find is revealed, even though these words aren't included in the ability's reminder text
If there are three on the battlefield, the number of tokens or +1/+1 counters is eight times the original number, and so on
In addition, you can always reach me on the MTGGoldfish Discord Server and the Vintage Streamers Discord
Like Rhystic, this card rewards teamwork and punishes selfishness
There are plenty of other rules associated with Oathbreaker, so make sure to read up on it if youre interested in that style of play